A detent device is one in which a moving part thereof is stopped due to the action of the device in a predetermined position. A multi-position rotary detent device is one in which a part which is capable of rotary movement is provided with a number of stopping points -- each being in detent position. The stopping point in a detent device is not a positive stop but one in which an additional amount of energy or force must be provided or utilized in order to move out of that position.
Detent devices in various configurations are well known in the art. A detent device which is stopped or which has its detent positions determined by mechanical action has a relatively short life due to the frictional engagement of parts. It is important in many applications to have a relatively simple detent device which is capable of long life and one which is not subject to severe wear due to frictional engagement of parts.